DE102021120194B3 - Process for the production of a real dental partial or full denture base - Google Patents

Abstract

The invention relates to a method for producing a real dental partial or full denture base, the method comprising the following method steps: i) providing a digital virtual model of the real dental partial or full denture base based on a gingiva situation with first color values, and ii) Manufacture of the real dental partial or full denture base based on the virtual model in a stereolithography-based generative process, wherein the photopolymerizable composition comprises at least one photochromic dye with a first hue whose light absorption properties change.The invention also relates to a dental partial or Full denture base and use of at least one photochromic dye in the method for producing a real dental partial and / or full denture base.

Description

The invention relates to a method for producing a real dental partial or full denture base using photochromic pigments, a dental partial or full denture base and the use of a photochromic dye or a polymerizable composition.

Additive manufacturing processes, such as the rapid prototyping process, for the production of dental products using colored layers, for example EP2671706A1 , are already known. A significant aesthetic disadvantage of the partial or full denture bases produced in this way is the production-related monochromaticity in the case of prefabrication and/or the lack of a reproduction of a natural-looking, patient-specific, individual, multicolored color gradient of the gums (gingiva) or the tooth. A disadvantage of the gum masks or gingival restorations of the prior art is their monotonous coloring and/or their lack of adaptation to the individual, nuanced color progression of a patient's dentition. So far, the gingival restorations have been made from a single red standardized shade. In order to create a natural-looking color gradient of the gingiva or dentures that is individually adapted to the dentition of a patient, complex post-treatment methods are necessary after the production of the actual partial or full denture base. A general method for producing three-dimensional objects using a photochromic component is known in the prior art in US5514519A disclosed. The composition disclosed there is polymerized using a laser with a wavelength of 325 nm, and the photochromic component in the already polymerized layer is then activated using a laser with a longer wavelength.

US 2014/0235747 A1 discloses a method of making three-dimensional objects from a composition comprising a thermally sensitive visual effect initiator. EP 3 184 096 A1 and EP 3 513 778 A1 disclose compositions with photochromic properties. U.S. 2008/0057000 A1 discloses photochromic dental materials for dental diagnostics. DE 690 19 991 T2 discloses a method for coloring medical prostheses which contain photochromic or thermochromic pigments in the surface or in the mass, which are reacted in a defined manner. DE 10 2016 208 908 A1 discloses photochromic compositions for 3D printing and U.S. 2020/0331201 A1 refers to processes for laser sintering of photochromic materials.

The object of the invention was therefore to provide an economical method for producing a real dental partial or full denture base whose patient-specific color gradient results from predefined target data during the production of the three-dimensional shaped body. Furthermore, there was the task of specifying an economical method that allows the production of high-quality, very aesthetic, natural-looking and, above all, individualized dentures by means of a generative method, such as rapid prototyping. In addition, there was the task of providing a high-quality, esthetic denture that has an esthetics similar to the gums as well as translucency and a patient-specific, mucosa-colored base or gingiva-colored prosthesis base corresponding to the natural patient-specific gums. Furthermore, there was the task of simplifying the procedure and shortening the duration of the procedure.

The object is achieved by the method according to claim 1, a dental partial or full denture base according to claim 16 and the use of a photochromic dye or a polymerizable composition according to claim 17.

1. i) Bereitstellen eines digitalen virtuellen Modells der realen dentalen Teil- oder Vollprothesenbasis auf Basis einer Gingiva-Situation mit ersten Farbwerten, die zu Voxeln des virtuellen Modells der realen dentalen Teil- oder Vollprothesenbasis zugeordnet sind, und optional Analyseinformationen bezüglich Geometrie, Morphologie und Farbverläufen der Gingiva und
2. ii) Herstellen der realen dentalen Teil- oder Vollprothesenbasis auf Basis des virtuellen Modells in einem stereolithographie-basierten generativen Verfahren, wobei das Verfahren die folgenden Schritte umfasst:
   1. a) Bereitstellen einer Schicht einer photopolymerisierbaren Zusammensetzung an einer Bauplattform, wobei die photopolymerisierbare Zusammensetzung umfasst Monomere oder eine Mischung von verschiedenen Monomeren und optional mindestens ein Additiv und/oder mindestens einen Farbstoff;
   2. b) Photopolymerisieren der Schicht in einer Belichtungsfläche, die einer Schicht des virtuellen Modells der realen dentalen Teil- oder Vollprothesenbasis entspricht, durch Belichten mit Strahlung der Wellenlänge L1;
   3. c) Bereitstellen einer weiteren Schicht der photopolymerisierbaren Zusammensetzung an der in b) photopolymerisierten Schicht durch eine Bewegung der Bauplattform, insbesondere wird die Bauplattform senkrecht, vorzugsweise entlang der z-Achse bewegt;
   4. d) Wiederholen der Schritte b) und c), bis sich ein Formkörper mit der Form der realen dentalen Teil- oder Vollprothesenbasis gebildet hat, insbesondere e) Erhalten einer realen dentalen Teil- oder Vollprothesenbasis,

wobei die photopolymerisierbare Zusammensetzung mindestens einen photochromen Farbstoff mit einem ersten Farbton, insbesondere mindestens ein photochromes Pigment, umfasst, dessen Lichtabsorptionseigenschaften sich ändert, indem nach Schritt ii) a), oder während Schritt ii) b) oder nach ii) b) die zu photopolymerisierende Schicht oder die photopolymerisierte Schicht eine Belichtung mindestens eines Voxels oder mindestens eines Musters von Voxeln in der Belichtungsfläche mit Strahlung einer Wellenlänge L2 erfolgt, die sich von der Strahlung der Wellenlänge L1 unterscheidet, insbesondere mit definierter Lichtintensität und/oder definierter Belichtungsdauer, wobei der mindestens eine photochrome Farbstoff einen zweiten Farbton annimmt.The process for producing a real dental partial or full denture base includes the following process steps:

1. i) Providing a digital virtual model of the real dental partial or full denture base based on a gingiva situation with first color values that are assigned to voxels of the virtual model of the real dental partial or full denture base, and optionally analysis information regarding geometry, morphology and color gradients gingiva and
2. ii) Manufacturing the real dental partial or full denture base based on the virtual model in a stereolithography-based generative process, the process comprising the following steps:
   1. a) providing a layer of a photopolymerizable composition on a construction platform, wherein the photopolymerizable composition comprises monomers or a mixture of different monomers and optionally at least one additive and/or at least one dye;
   2. b) photopolymerizing the layer in an exposure area corresponding to a layer of the virtual model of the real dental partial or full denture base by exposure to radiation of wavelength L1;
   3. c) providing a further layer of the photopolymerizable composition on the in b) the photopolymerized layer by moving the construction platform, in particular the construction platform is moved vertically, preferably along the z-axis;
   4. d) repeating steps b) and c) until a shaped body has formed with the shape of the real dental partial or full denture base, in particular e) obtaining a real dental partial or full denture base,

wherein the photopolymerizable composition comprises at least one photochromic dye with a first hue, in particular at least one photochromic pigment, whose light absorption properties change by after step ii) a), or during step ii) b) or after ii) b) the to be photopolymerized layer or the photopolymerized layer, at least one voxel or at least one pattern of voxels in the exposure area is exposed to radiation with a wavelength L2 that differs from the radiation with a wavelength L1, in particular with a defined light intensity and/or defined exposure duration, with the at least one photochromic dye takes on a second hue.

Compared to the prior art, the method according to the invention has the advantage that an adjustment of the color progression of the real dental partial or full denture base produced to real scanned color values of the gingiva of a patient is made possible. Providing a layer of a photopolymerizable composition on a build platform means that a layer of a photopolymerizable composition is provided on a build platform or under a build platform. So whether the polymerizable layer is provided on or under the construction platform depends on the 3D printer used. For a printer according to 2 the layer to be polymerized is created on the construction platform and exposed from above while in the 3D printer according to 3 the exposure takes place from below and the layer to be polymerized is accordingly provided under the construction platform. The direction of movement of the build platform is usually along the z-axis of the 3D printer. Photopolymerizable is used synonymously with radiation induced polymerizable, in particular UV and/or Vis rays induced polymerizable, particularly preferably light-induced polymerizable. Photopolymerized layer is synonymous with layer polymerized by means of electromagnetic rays.

Accordingly, providing a further layer of the photopolymerizable composition on the photopolymerized layer in b) by moving the construction platform means that the layer can be provided on or under the photopolymerized layer by moving the construction platform perpendicularly to the photopolymerized layer by the layer thickness of a layer or moved by more than one layer to provide another layer of photopolymerizable composition on top of the photopolymerized layer. If the construction platform has been moved by more than one layer, it is moved back to the distance of one layer in relation to the initial situation before photopolymerization.

Die Leistung P ist P=W/t; in diesem Fall ist es die Strahlungsleistung. Damit kann man für die Lichtintensität auch $$I=P\text{/}A$$

schreiben.The light intensity / describes the radiant energy W that hits a surface A perpendicularly in the time t. $$I=W\text{/}A\cdot t$$

The power P is P=W/t; in this case it is the radiant power. You can use this for the light intensity as well $$I=P\text{/}A$$

write.

Exposure time (or exposure duration) is the length of time that a photosensitive medium is exposed to light.

Light absorption is a physical interaction in which light gives off its energy to matter. Light absorption is a special case of the more general physical phenomenon of absorption. When electromagnetic radiation is absorbed, an electron of an atom changes from an energetically more favorable state to a state with higher energy, this happens through the "electron jump". One speaks of electronic excitation. The change in the light absorption properties of the photochromic dye or pigment can be detected in a changed UV/Vis spectrum of the photochromic dye or pigment between the states of a) exposure to wavelength L1 and b) exposure to radiation of wavelength L2.

Using the new technology, depending on the radiation of the wavelength L2 and the light intensity and/or exposure time, a coloring can also be changed between the layers or layers, which corresponds to a color gradient in the z-direction. This is possible in particular without changing the monomer bath, for example the photochromic, light-curing composition. Advantageously, a color gradient within a layer can also be made possible in this way if partial polymerization takes place during the coloring step or between two coloring steps. If desired, teeth and gums can be made in one process and from one material.

An exposure surface of the shaped body is irradiated, preferably by means of a surface-emitting radiation source, in particular a light source, preferably by means of a projector and/or beamer. The layer to be photopolymerized is partially polymerized by means of radiation of wavelength L1 and a first color tone of the respective photochromic pigment is produced. The layer to be photopolymerized is fully polymerized by means of radiation of wavelength L2 and a second shade of the respective photochromic pigment is permanently fixed. In order to activate and fix the second shade of the respective photochromic pigment, the respectively defined light intensity and/or defined exposure time must be taken into account.

A partial or full denture base should preferably be understood to mean a gingival imitation as a reproduction of a missing gum area, a missing gingiva or a missing gingival area, in particular for an area of the gingiva. A partial or full denture base can advantageously also be part of a prosthetic treatment with dentures. In additive processes such as stereolithography, the prosthesis base is made from a gingiva-colored, polymerizable, dental composition. Stereolithography methods are among the rapid prototyping methods. The rapid prototyping processes are three-dimensional printing processes. In the present case, light (UV and/or Vis radiation) polymerizable (curable) monomers or a photopolymerizable composition comprising a mixture of monomers are polymerized, preferably with UV light. Based on a 3D model in STL format, this is optionally provided with a support structure, also known as a support, to increase stability in the bath on or under the construction platform. The model obtained in this way is then digitally divided into individual layers, the process is referred to as slicing. The individual layers are read into a machine control and adjusted accordingly. The machine control regulates the sequence of movements and the exposure process. The STL interface (STereoLithography, Standard Tessellation Language) is a standard interface of many CAD systems. It provides geometric information of three-dimensional data models for production using additive manufacturing processes/3D printing or rapid prototyping systems.

In computer graphics, voxel (composed of the English volume vox and el from elements) denotes a grid point (“image” point, data element) in a three-dimensional grid. This corresponds to a pixel in a 2D image, a raster graphic. For a spatial data set that is in discretized form in Cartesian coordinates, voxel denotes the discrete value at an XYZ coordinate of the data set. The data contained in voxel grids are often color values that are determined using volume graphics for visualization. This form of data representation is mainly used in medical imaging processes, where the discrete values can be understood as density (bones, fatty tissue) and visualized accordingly.

The analysis information regarding the geometry, morphology and color gradients of the gingiva is carried out using a gingiva indexing device, which makes it possible to map areas of the gingiva, in particular the human gingiva, using defined red color regions, i.e. to spatially and geometrically record, analyze and to document. The gingiva indexing device allows in particular a reproducible detection, analysis and/or documentation of the gingiva situation with regard to the red tones, their color gradients and/or the morphology of the gingiva situation. The gingiva indexing device enables the topographical assignment of the shades in the restoration. The indexing device and the method according to the invention allow the gum colors or the gum characteristics to be recorded.

Dyes are inorganic or organic substances which, in contrast to the pigments, are soluble, preferably completely soluble, in their application medium (water or organic solvents), here monomer-containing photopolymerizable composition. Pigments are particulate substances that do not dissolve in their application medium, in this case the photopolymerizable composition, and therefore have to be finely distributed in a binder. The application medium is the substance in which the pigment is incorporated, for example in binders such as oils or plastics. In biology, the term pigment refers to all coloring substances in a living organism. The color stimulus is created in pigments by absorption and remission (scattering or reflection) of certain frequency components of visible light. Solid state properties such as crystal structure, crystal modification, particle size and particle size distribution, the latter due to the specific surface area, are decisive for the properties of the pigments.

Photochromic dyes are dyes that react to irradiation with light (radiation, in particular electromagnetic radiation), in particular UV light (sunlight or black light), with a React to reversible or irreversible color changes. The light changes the chemical structure of the dyes and thus their absorption behavior (photochromism).

Photochromic pigments, in particular encapsulated, photochromic dyes, are pigments that change their hue under the influence of radiation, i.e. light of wavelength L2 and optionally defined intensity. In the case of use in the dental field, health safety is of particular advantage. For example, fluorescent pigments or encapsulated photochromic dyes, in particular encapsulated with an organic or bio-based and/or polymerized material, could be used. Particularly preferred are photochromic dyes that are completely enveloped by a polymeric material, i.e., are completely encapsulated.

A further embodiment provides that the voxel exposed to the radiation of wavelength L2 or the pattern has a hue that corresponds to the respective associated color value of the respective corresponding voxel of the virtual model of the real dental partial or full denture base.

Advantageously, the patient-specific color gradient of the partial or full denture base results from predefined target data during the production of the three-dimensional partial or full denture base. Using a generative process, a patient-specific gum (and tooth) replacement is created with regard to the color gradient. Subsequent treatment of the generatively manufactured dental partial or full denture base to adapt the color gradient to the patient's gingival situation is no longer necessary, so that the process for manufacturing an aesthetic, natural-looking and, above all, patient-specific dental partial or full denture base is significantly shortened. A natural-looking translucency and typical gum characteristics of a patient can be reproduced directly using the generative manufacturing process.

A voxel-by-voxel irradiation with a defined wavelength guarantees a high spatial selectivity of the color application. Undesirable dispersion of the colors can be largely avoided in particular in the case of a previous partial polymerization, in particular with irradiation with light of wavelength L1, of the respective layer.

• - digitales Erfassen des Gebisses eines Patienten mittels eines 3D-Scanners, insbesondere ein digitales Erfassen einer Gingiva-Situation eines Patienten;
• - Analyse mindestens eines Teils der digitalen 3D-Daten bezüglich der Morphologie des Gebisses als Basis zur Herstellung einer realen Teil- oder Vollprothesenbasis, wobei die Analyse manuell und/oder digital erfolgt, wobei die digitale Analyse eine Analyse mindestens eines Bereiches der Gingiva-Situation in Bezug auf ihre roten Farbtöne, die Position der roten Farbtöne, den Farbverlauf der roten Farbtöne, deren Geometrie und/oder deren Morphologie umfasst, wobei Gingiva-Informationen erhalten werden, insbesondere in Form einer Gingiva-Kartierung; und/oder
• - optional ein Herstellen eines virtuellen oder realen Modells einer Gingiva-Restauration als Nachbildung einer fehlenden Zahnfleischpartie und/oder einer Gingiva-Partie; wobei a) die digital erfassten 3D- und/oder 2D-Daten der Gingiva-Situation einem digitalen virtuellen Modell der realen dentalen Teil- oder Vollprothesenbasis auf Basis einer Gingiva-Situation mit ersten Farbwerten entsprechen oder b) die digital erfassten 3D- und/oder 2D-Daten der Gingiva-Situation werden optional digital in Bezug auf die Geometrie, Morphologie und/oder Farbverläufe bearbeitet und optional werden Analyseinformationen bezüglich Geometrie, Morphologie und Farbverläufen der Gingiva zugeordnet, wobei diese 3D- und/oder 2D-Daten einem digitalen virtuellen Modell der realen dentalen Teil- oder Vollprothesenbasis auf Basis einer Gingiva-Situation mit ersten Farbwerten entsprechen,

wobei die ersten Farbwerte im Munsell-Farbraum in einem Bereich von 5,3R-6,5YR liegen, wobei Dateiformate umfassen STP, IGES, STL, X3D, COLLADA, WRL, OBJ, PLY, AMF.According to a further embodiment, the gingiva situation is digitally recorded using a 3D and/or a 2D scanner, with an intraoral scanning of a patient's oral cavity taking place in particular, with the 3D and/or the 2D scanner having a CAD interface 3D and/or 2D data is available. 2D and/or 3D scanners preferably scan in the wavelength range from 100 nm to 1300 nm, in particular from 280 to 850 nm.
According to a further embodiment, the method comprises the steps:

• - Digital detection of a patient's dentition by means of a 3D scanner, in particular digital detection of a patient's gingiva situation;
• - Analysis of at least part of the digital 3D data regarding the morphology of the dentition as a basis for the production of a real partial or full denture base, the analysis being carried out manually and/or digitally, the digital analysis being an analysis of at least one area of the gingival situation in relating to their red hues, the position of the red hues, the gradient of the red hues, their geometry and/or their morphology, obtaining gingival information, in particular in the form of gingival mapping; and or
• - optional production of a virtual or real model of a gingival restoration as a replica of a missing gum area and/or a gingival area; wherein a) the digitally recorded 3D and/or 2D data of the gingival situation corresponds to a digital virtual model of the real dental partial or full denture base based on a gingival situation with first color values or b) the digitally recorded 3D and/or 2D data of the gingiva situation is optionally processed digitally with regard to geometry, morphology and/or color gradients and analysis information with regard to geometry, morphology and color gradients of the gingiva is optionally assigned, with this 3D and/or 2D data being a digital virtual model correspond to the real dental partial or full denture base based on a gingiva situation with first color values,

where the first color values are in the Munsell color space in a range of 5.3R-6.5YR, where file formats include STP, IGES, STL, X3D, COLLADA, WRL, OBJ, PLY, AMF.

• - Erstellen eines digitalen, virtuellen Modells der dentalen Teil- oder Vollprothesenbasis auf Basis zuvor erhobener Analysedaten;
• - Zuordnen von einzelnen Farbwerten zu einzelnen Voxeln des virtuellen Modells, wobei die Farbwerte entweder den ursprünglich digital erfassten Farbwerten des gescannten Mundraumes, insbesondere Gebisses, vorzugsweise eines Patienten, bevorzugt der Gingiva, entsprechen, einer Datenbank entnommen sind oder die Zuordnung frei nach Belieben erfolgt;
• - Umwandeln des aus einem Mundraumscan des Patienten entnommenen realen Farbverlaufs in einen Datensatz;
• - Übersetzen des digitalen Farbverlaufs in verschiedene Wellenlängen des eingestrahlten Lichts bei Verwendung photochromer Pigmente;
• - Herstellen der dentalen Teil- oder Vollprothesenbasis mittels 3D-Stereolithographie; und optional Anpassen eines Herstellungsprozesses an real gescannte Daten.

The invention also relates to a method which comprises the additional steps:

• - Creation of a digital, virtual model of the dental partial or full denture base based on previously collected analysis data;
• - Assignment of individual color values to individual voxels of the virtual model, the Color values either correspond to the originally digitally recorded color values of the scanned oral cavity, in particular dentition, preferably of a patient, preferably the gingiva, are taken from a database, or the assignment is made freely at will;
• - converting the real color progression taken from an oral cavity scan of the patient into a data set;
• - Translating the digital color gradient into different wavelengths of the incident light when using photochromic pigments;
• - Manufacture of the dental partial or full denture base using 3D stereolithography; and optionally adapting a manufacturing process to real scanned data.

The digital virtual model of the real dental partial or full denture base based on a gingiva situation with first color values is preferably available as a data record in an STL format.

As a result, patient-specific target data for creating a real partial or full denture base can be created in an advantageous manner. This target data can advantageously be visualized as a three-dimensional virtual model of the real partial or full denture base to be created via suitable interfaces and made available for the generative manufacturing process for further processing. There is no need to manually create a negative impression of the patient's dentition.

According to a further embodiment, it is provided that the first color values result from the digitally recorded gingiva situation and/or the analysis information regarding the geometry, morphology and color gradients of the gingiva.

The individual voxels of the virtual model of the real partial or full prosthesis base to be created are thus advantageously already assigned first color values which correspond to the original color values recorded during intraoral scanning. This results in an initial imaging of the gingiva situation with original color values as a starting point for possible corrections or for a simulation of the partial or full denture base to be produced. The dentist can include further analysis information regarding the geometry, morphology and color gradients of the gingiva.

According to a further embodiment, the method comprises as a further method step, in particular in step i), an additional assignment of second color values, wherein the additional assignment of second color values according to a predefined model, which is stored in a database, and / or free of a predefined template is done.

The individual voxels of the virtual model of the real partial or full denture base to be created can be assigned any second color values by the dentist, for example. In this case, either predefined model values already stored in a database can be used, or color values can be assigned to the voxels without a template at the discretion of the dentist. This means that aesthetic and individual aspects can also be taken into account.

Color values and/or color scales of standardized, prefabricated imitation gums, dental implants and/or dental prostheses, which each form a starting point and are then adapted to the specific patient, can be stored in a database. A color nuance and the formation of different color regions is possible in the x, y and z directions.

Another embodiment provides that the second hue of the at least one photochromic dye, in particular the at least one photochromic pigment, corresponds to the first or second color value of the respective voxel of the virtual model of the partial or full denture base.

Through site-selective irradiation of a partially polymerized layer with radiation of the specific wavelength L2, the specific photochromic dye or the specific photochromic pigment assumes exactly the target color value that was previously specified in the virtual model of the dental partial or full denture base to be produced. In this way, the target and actual color values match at the respective point on the dental partial or full denture base. A color gradient of the real dental partial or full denture base resulting from irradiation of a region of the shaped body being formed with radiation of a plurality of specific wavelengths L2 is identical to the color gradient predefined in the virtual model. The color values specified in the virtual model represent reference values, so to speak, the realization of which on the real dental partial or full denture base is the aim of the method according to the invention, the desired color values being realized by means of the respective second color tones of the photochromic pigments.

In a further embodiment, upon irradiation with radiation of wavelength L2, the second hue of the at least one photochromic dye, in particular of the at least one photochromic pigment, permanently fixed in the composition by polymerizing, preferably photopolymerizing, the monomers and optionally prepolymers.

This advantageously makes the photochromism of the at least one dye, in particular the at least one photochromic pigment, irreversible, i.e. the dental partial or full denture base permanently retains the color nuance obtained at the end of the generative production by irradiation with radiation of the specific wavelength L2 in each case. The location-selective application of color to the molded body and the color gradients created are retained even after the manufacturing process is complete.

In a further embodiment, the at least one photochromic dye, in particular the at least one photochromic pigment, is organic or inorganic.

Health safety has top priority because of wearing the dental partial or full denture base in the mouth.

In particular, the photochromic dye, particularly the photochromic pigment, has a composition represented by the formula: Ba _(ab) Ca _b Mg _c Si _d O _e : Fe _f MgM' _h where 1.8≦a≦2.2 , 0 ≤ b ≤ 0.1, 1.4 ≤ c < 3.5, 1.8 ≤ d ≤ 2 .2, e = (a + c + 2d), 0.0001 ≤ f, 0.0001 ≤ g , 0 ≤ h, M is at least one of Al and Eu, and M' is at least one element selected from the group consisting of Na, B, K, Nd, Li, S, C, Ti, V, Mn, Cr, Cu , Ni, Co, Ge, Zn, Ga, Zr, Y, Nb, In, Ag, Mo, Sn, Sb, Bi, Ta, W, La, Ce, Pr, Nd, Sm, Gd, Er, Ho, Tb , Tm, Yb, Lu, P, Cd, and Pb.

In the formula (1), 1.9≦a≦2.1 is preferred. In addition, 0≦b≦0.01 is more preferred, 0≦b≦0.001 is particularly preferred, with b=0 being even more preferred. Particularly preferred is 2.0≦c≦3.5, and 2.5≦c≦3 is more preferred. 1.9≦d≦2.1 is preferred. Further, 0.0005≦f is preferable, 0.001≦f is more preferable, and 0.002≦f is more preferable. Even more preferably f≦2, in particular f≦1, preferably f≦0.5, preferably f≦0.2. For g, g is preferably greater than or equal to 0.0005, in particular g is greater than or equal to 0.001. Particularly preferred is g ≤ 0.025, more preferred g ≤ 0.012. Furthermore, 0.0001≦h is preferred, preferably 0.0005≦h, preferably 0.001≦h. Particularly preferred is h≦0.025, particularly preferred h≦0.012. This makes it possible to provide a photochromic dye exhibiting higher photochromism. Furthermore, it is particularly preferred in the formula (1) that M=Al and h=0.

The photochromic substance of the present invention having the above composition is a barium magnesium silicate-based substance. The photochromic dye of the present invention has a tridymite structure, ie, a structure in which SiO ₄ ; -Tetrahydrons are connected to each other via their vertices, thus forming a three-dimensional tunnel structure. The photochromic substance of the present invention has a structure in which a certain percentage of silicon ions (Si ⁴⁺ ) in the SiO ₄ tetrahydrons are replaced with a magnesium ion (Mg ²⁺ ) and a barium ion (Ba ²⁺ ) and the like.

With the above composition, the photochromic dye of the present invention exhibits a good photochromic property in a visible light region. For example, the photochromic dye of the present invention has a property of changing its color from white to red (pink) when blue light (eg, light having a wavelength of 405 nm) is applied and a property of changing its color from white to deep red (pink) upon exposure to ultraviolet light (e.g., light with a wavelength of 365 nm). That is, with the aforesaid composition, the resulting color of the photochromic dye can be adjusted, i.e., how much the color of the photochromic dye (reflectance) changes depending on a wavelength of light with which the photochromic substance is irradiated.

A photochromism property of a barium magnesium silicate can be further improved by adding aluminum (Al) and/or europium (Eu), which is known to cause an improvement in photochromism, in addition to barium magnesium silicate in addition to iron (Fe).

A compound containing at least one piperidine ring and having a molecular weight equal to or greater than 1000 g/mol also exhibits polychromy.

As used herein, a photochromic dye is a photochromic dye which may be in the form of a liquid or a solid. A photochromic pigment is a photochromic dye that is in the form of a solid and is insoluble in the application medium, e.g. in the composition comprising monomers.

In a further embodiment, the at least one photochromic dye, in particular the at least one photochromic pigment, is a photochromic inorganic pigment, in particular comprising an oxide of copper, samarium, terbium, praseodymium and/or europium.

The organic photochromic dyes can be used either alone or in combination with one or more other photochromic, inorganic photochromic pigments, for example including rare earth doped metal oxide nanoparticles (e.g. zirconium oxide, yttria, zinc oxide, copper oxide, lanthana, gadolinium oxide, praseodymium), oxides and the like and combinations thereof doped with rare earths such as lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium and the like and combinations thereof, metal nanoparticles (eg, gold, Silver, platinum, palladium, iridium, rhenium, mercury, ruthenium, osmium, copper, nickel and the like) and combinations thereof), semiconductor nanoparticles for example, Group II-VI.

A full range of polychromatic colors can be developed using one or more oxides selected from copper, samarium, terbium, praseodymium and europium oxides for activation.

A further embodiment provides that the at least one photochromic dye is a photochromic organic dye, preferably at least one photochromic organic pigment. In a further embodiment it is provided that the at least one photochromic dye comprises naphthacenquinone, spiropyran, spirooxazine, chromene, a naphthopyran compound, a spiro[1,8a-indolizine] derivative, a spiro[1,8a-dihydrindolizine] derivative spiro[1,8a-tetrahydroindolizine] derivative, a spiro[fluorene-9,1[1,8a]dihydroindolizine] derivative, camphorquinone and/or phenanthrenequinone. Equally suitable are spirooxazines, spiroindolinonaphthoxazines and/or chromenes, such as Reversacol Rush Yellow, Reversacol Midnight Gray (James Robinson) and optionally 2-spiroadamantane-2H-naphtho[1,2-b]pyran, 2-methyl-2-(paradiethylaminophenyl )-2H-naphtho[1,2-b]pyran, 1,3,3-triphenyl-3H-naphtho[2,1-b]pyran.

Naphthacenquinones are advantageous because, when irradiated with radiation of wavelength L2, they exhibit a clear color change from yellow to yellow-orange to orange to red, which is suitable for simulating a gum characteristic.

Photochromic dyes can have auxochromic substituents.

In a further embodiment, the second hue includes color values of the YCM color space, in particular red or yellow color nuances of the YCM color space.

The at least one photochromic dye, in particular the at least one photochromic pigment, has color values of the YCM color space, in particular red or yellow color nuances, when irradiated with radiation of wavelength L2. The gingiva with its translucency can be realistically reproduced using these color nuances. Mixing different color values also results in color effects that are very similar to those of natural gingiva.

A color region in the area of the dental partial or full denture base, in particular in the area of the gingiva, preferably has a shade of red. Alternatively, a color region can also have different defined shades of red in a defined arrangement or in a typical color gradient. The color regions can preferably be three-dimensional color bodies, which preferably reproduce typical red color gradients and/or a typical morphology of an area of a gingiva. In one embodiment, the method according to the invention for producing a real dental partial or full denture base therefore has a lifelike reproduction of the colors, color gradients of the red tones of the natural gingiva, preferably at least 2 to 5000 different red tones, particularly preferably 5 to 2000 different red tones.

A color region corresponds to a delimited two- or three-dimensional area comprising at least one shade of red. It is preferred here if the color regions are arranged from a light shade of red to a dark shade of red and/or from a red with yellow components to a red with blue components. Advantageous color gradients include a Kodak color gamut, RGB model, CMYK model, Pantone, HKS fans, RAL color system, or other color systems familiar to those skilled in the art that include shades of red or shades of red.

In a further embodiment, it is provided that the exposure of at least one voxel or at least one pattern of voxels in the exposure area to radiation of wavelengths L1 and L2 is carried out by means of a surface-emitting light source, in particular by means of a projector and/or a beamer, with the projector and /or beamer images a projection surface with radiation of locally different wavelengths and/or intensities on the surface of the photopolymerizable composition or guides it over the surface, the beamer preferably being an LED beamer, particularly preferably a UV-LED beamer.

As a result, the duration of the irradiation of a layer to be photopolymerized of the molding being formed is shortened overall, since an entire area is exposed and not point by point layer to be photopolymerized is removed. Overall, the production process of generative stereolithography is thus shortened.

The exposure surface forms a layer of the real partial or full denture and corresponds to a layer (x,y data in the z-plane) of the virtual model of the digital dental partial or full denture base. The exposure area therefore has a defined outer contour that lies on the outer surface of the prosthesis base.

A high UV irradiance in combination with a large and evenly irradiated area are the main features of the UV LED projector. The UV LED modules are water-cooled, high-performance UV floodlights with intelligent LED drivers. The absence of ineffective infrared radiation significantly reduces heat compared to traditional UV lamps. The high irradiance enables extremely short processing times. For example, wavelengths of 365, 385, 395, 405 and 450 nm are available for irradiating the photochromic dyes or pigments.

In the well-known rapid prototyping processes, UV LED projectors are increasingly being used in addition to ultraviolet (UV) lasers. Methods for this are, for example, from EP 1880830 A1 and the EP 1894705 A2 known. A disadvantage of lasers is their punctiform exposure field. The UV light from the light source is projected onto a light-curing plastic as an exposure field. Optics and a surface light modulator are used for imaging. Due to the optics, there is an inhomogeneous light distribution or intensity distribution. The edge areas of the exposure field typically have a lower intensity than the areas in the center of the exposure field. This effect, also known as barrel image, means that the light-curing plastic does not have the same intensity at every point and therefore hardens differently, i.e. inhomogeneously. the EP 1 982 824 A2 suggests homogenizing the intensity distribution by reducing the lighter pixels of the UV projector to the intensity level of the pixels at the edge using a gray distribution.

In a further embodiment it is provided that the method comprises the step: a respective conversion of a second hue into the specific wavelength L2, wherein by using several photochromic pigments and activation by different specific wavelengths L2 of the radiation and intensities different color values of the YCM color space, of the RGB color space, the Munsell color space or the L*a*b* color space.

A UV LED beamer preferably has irradiation segments with different wavelengths and intensities, so that a large number of photochromic dyes in the respective layer to be photopolymerized are excited to change color at the same time. Ideally, there is software that converts the target color values of the respective voxels of the virtual model of the dental partial or full denture base to be produced into specific wavelengths L2 and controls the UV LED projector segment by segment during irradiation with regard to wavelength, light intensity and exposure time. Alternatively, a surface light modulator is used, which has a large number of controllable, tiltable micromirrors arranged in rows and columns, in which the light from a surface-emitting light source is imaged via optics and an exposure field of the imaged light source is guided over a projection surface with the surface light modulator, with a number of pixels that increases towards the center of the exposure field is not illuminated, so that the light intensity of all pixels illuminated on the projection surface is homogenized in the time integral. For example, the particularly well suited ^DLP® chips from Texas Instruments can be used as area light modulators.

Alternatively, a laser system can be used. Both the beamer and the laser system preferably emit light of a wavelength selected from 180 to 650 nm, preferably from 230 to 450 nm. In general, polychromatic light sources can be used as beamers. Beamers with a resolution of greater than or equal to 800×600 pixels are preferred, preferably greater than or equal to 1920×1080 pixels. According to the invention, the planar light source, the planar light modulator and the optics, in particular a lens system, form an arrangement. The planar light source, the planar light modulator and the optics, in particular a lens system, are also present as an arrangement in a structural unit.

In a further embodiment, the invention relates to a dental partial or full prosthesis base which was produced using the method according to the invention, in particular at least one prosthesis base plate, in particular a gingiva imitation as a reproduction of a missing gum area, a missing gingiva or a missing gingiva part.

A gingiva restoration according to the invention has a lifelike reproduction of the colors, color gradients of the red tones of the natural gingiva, preferably at least 2 to 5000 different shades of red, particularly preferably 5 to 2000 different shades of red.

In a further embodiment, the invention relates to the use of at least one photochromic dye in a method for producing a real dental partial and/or full denture base, whereby color values of the YCM color space, of the RGB color space, the Munsell color space or the L*a*b* color space.

Further details, features and advantages of the invention result from the drawings and from the following description of preferred embodiments with reference to the drawings. The drawings merely illustrate exemplary embodiments of the invention, which do not restrict the essential idea of the invention.

Reference List

0

apparatus

1

UV LED projector

2

lens system

3

Arrangement of the planar light source (1), the planar light modulator (4) and/or the lens system/optics

4

Area light modulator

5

window

6

photopolymerizable composition, in particular light-curing, photochromic composition

8th

container

10

molding

12

build platform

100

Process for the production of a real dental partial or full denture base

101

3D scanning of a denture

102

analysis

103

Creation of a virtual dental partial or full denture base

104

Assigning color values to voxels

105

Manufacturing a real dental partial or full denture base using stereolithography

character list

• 1 shows a flow chart of the individual method steps of the method according to the invention.
• 2 shows a schematic cross-sectional view of a structure for implementing the method according to the invention.
• 3 shows a 3D printer with exposure from below.

• 1 zeigt ein Flussdiagramm der einzelnen Verfahrensschritte des erfindungsgemäßen Verfahrens. 1 zeigt ein Flussdiagramm zur Darstellung der verschiedenen Verfahrensschritte des Verfahrens 100 zur Herstellung einer realen dentalen Teil- oder Vollprothesenbasis. In Schritt 101 wird das Gebiss eines Patienten mittels eines 3D-Scanners digital erfasst. Insbesondere wird eine Gingiva-Situation eines Patienten digital erfasst. In Schritt 102 erfolgt eine digitale Analyse mindestens eines Teils der digitalen 3D-Daten bezüglich der Morphologie des Gebisses als Basis zur Herstellung einer realen Teil- oder Vollprothesenbasis. Die digitale Analyse umfasst eine Analyse mindestens eines Bereiches der Gingiva-Situation in Bezug auf ihre roten Farbtöne, die Position der roten Farbtöne, den Farbverlauf der roten Farbtöne, deren Geometrie und/oder deren Morphologie, wobei die Analyse manuell und/oder digital erfolgt, und Gingiva-Informationen erhalten werden, insbesondere in Form einer Gingiva-Kartierung. Optional wird ein virtuelles oder reales Modell einer Gingiva-Restauration als Nachbildung der fehlenden Zahnfleischpartie bzw. Gingiva-Partie hergestellt.

Exemplary embodiments of the invention are explained below:

• 1 shows a flow chart of the individual method steps of the method according to the invention. 1 FIG. 10 shows a flow chart for representing the various method steps of the method 100 for producing a real dental partial or full denture base. In step 101, a patient's teeth are digitally recorded using a 3D scanner. In particular, a patient's gingival situation is recorded digitally. In step 102, at least part of the digital 3D data relating to the morphology of the teeth is digitally analyzed as the basis for producing a real partial or full denture base. The digital analysis includes an analysis of at least one area of the gingiva situation in terms of its red shades, the position of the red shades, the color progression of the red shades, their geometry and/or their morphology, the analysis being carried out manually and/or digitally, and gingival information is obtained, particularly in the form of gingival mapping. Optionally, a virtual or real model of a gingiva restoration is produced as a replica of the missing gum area or gingiva area.

In step 103, a virtual model of the dental partial or full denture base is created on the basis of the previously collected analysis data. In step 104, individual color values are assigned to individual voxels of the virtual model, the color values either corresponding to the originally digitally recorded color values of the scanned dentition, in particular the gingiva, or being taken from a database, or the assignment being made freely as desired. First, the real color gradient taken from a mouth scan of the patient is converted into a data set. This digital color gradient can then be translated into different wavelengths of the incident light when using photochromic dyes, in particular photochromic pigments. In method step 105, the real partial or full denture base is produced by means of stereolithography. Thus, in one embodiment, the processes are adapted to real scanned data.

2 shows the apparatus 0 for carrying out the stereolithographic method 105. In a container 8 there is a construction platform 12 which can be moved in the vertical direction. In the container 8 there is a liquid, photochromic composition 6 (light-curing liquid plastic) containing, for example, epoxy resin or an acrylate(s). In one embodiment, the light-curing composition comprises electromagnetic radiation-polymerizable monomers, preferably dental, UV- and/or Vis-polymerizable monomers. The photochromic dye is already present in the liquid, photopolymerizable composition, in particular photochromic composition 6, in microencapsulated form. In an alternative embodiment, fluorescent pigments or encapsulated dyes, in particular encapsulated with an organic or bio-based polymer, are used. The activation of the various photochromic color pigments could be triggered, for example, by a projector which images a projection surface with locally different wavelengths and/or intensities on the surface of the bath containing the photochromic composition or moves it over its surface. When using photochromic dyes, the color values are converted into wavelengths.

A UV LED projector 1 which emits ultraviolet light (UV light) is radiated onto a surface light modulator 4 . The UV LED projector 1 has a resolution of 1920×1080 pixels, which radiate as a rectangular area on the surface of a chip of the UV LED projector 1. The area light modulator 4 comprises a large number of controllable micromirrors, with which the light from the UV LED projector 1 is reflected and imaged onto the surface of a liquid, light-curing plastic 6 with the aid of a lens system 2 . The micro mirrors are in 1 shown as differently oriented small rectangles on a surface of the surface light modulator 4. The liquid light-curing composition 6 is arranged in the container 8 which is open at the top to the surface light modulator 4 or the lens system 2 .

The lens system 2, which is 1 shown schematically only as a simple lens, forms the surface of the pixels of the UV LED projector 1 onto the surface of the light-curing, photochromic composition 6 comprising polymerizable monomers and at least one photochromic dye or photochromic pigment. With the help of a suitable motor (not shown), the UV LED projector 1 is moved over the container 8 and the surface of the light-curing composition 6 is thereby swept with the exposure field, so that each line of the chip of the UV LED projector 1 is exposed to each Point completely overruns or can overrun.

The resulting exposure field on the surface of the light-curing composition 6 polymerizes the monomers so that a solid molded body 10 is formed. The solid mold 10 is mounted on a construction platform 12, which is slowly lowered layer by layer so that the upper surface of the mold 10 is wetted by the liquid light-curing composition 6 and a new polymerized layer can be produced on the mold 10 using the exposure field . The photopolymerization, synonymous with radiation-induced polymerization, in particular UV and/or Vis polymerization, is continued layer by layer until the resulting molded body 10 matches the virtual model of the dental partial or full denture base.

The UV LED projector is designed to emit both light of wavelength L1 for partial polymerization of the light-curing, photochromic composition 6 and light of wavelength L2 for permanent fixing of the second hue of the respective photochromic pigment. If the UV LED projector forms a projection surface with locally different wavelengths/intensities on the surface of the monomer bath of the polymerizable composition or if it guides it over the surface, different specific wavelengths L2 of different photochromic color pigments can be realized and the respective second color of the respective photochromic color pigments are generated on or in the shaped body 10. The more selectable ranges of radiation of different wavelengths the UV LED beamer makes available and the more photochromic dyes whose specific adjustable wavelengths L2 match the wavelengths of the UV LED beamers are in the monomer bath, the more color tones can be applied to the molded body will be realized. In order to generate a color progression of a real dental partial or full denture base using the method according to the invention, it is ultimately necessary to convert second color tones into specific wavelengths L2 of the radiation. Furthermore, the defined light intensity and/or defined exposure time required for activating and permanently fixing the respective photochromic pigment, which depends on the respective wavelength, must also be taken into account.

3 shows a 3D printer in which the exposure takes place from below and the to be polymerized The resulting layer is accordingly provided under the construction platform 12 (bottom-up 3D stereolithography). In this case, the construction platform 12 is successively moved vertically (along the z-axis) from bottom to top after each photopolymerization step. The exposure by means of a UV LED projector 1 takes place from below through a translucent window 5 of the container 8 in which the photochromic, light-curing composition 6 is located. The molded body 10 is formed in layers below the construction platform 12. A 3D printer from the manufacturer B9Creations based in Rapid City in the USA is preferably used.

Claims (17)

Method for producing a real dental partial or full denture base (100), the method comprising the following method steps: i) Providing a digital virtual model of the real dental partial or full denture base based on a gingiva situation with first color values that are assigned to voxels of the virtual model of the real dental partial or full denture base, and optionally analysis information regarding geometry, morphology and color gradients gingiva, and ii) Manufacturing the real dental partial or full denture base based on the virtual model in a stereolithography-based generative process, the process comprising the following steps: a) providing a layer of a photopolymerizable composition on a construction platform (12), the photopolymerizable composition comprising monomers or a mixture of different monomers and optionally at least one additive and/or at least one dye; b) photopolymerizing the layer in an exposure area corresponding to a layer of the virtual model of the real dental partial or full denture base by exposure to radiation of wavelength L1; c) providing a further layer of the photopolymerizable composition on the layer photopolymerized in b) by moving the build platform (12); d) Repeating steps b) and c) until a shaped body (10) has formed with the shape of the real dental partial or full denture base, wherein the photopolymerizable composition comprises at least one photochromic dye with a first hue, the light absorption properties of which change , in that, after step ii) a), or during step ii) b) or after ii) b), the layer to be photopolymerized or the photopolymerized layer is exposed to at least one voxel or at least one pattern of voxels in the exposure area with radiation of wavelength L2 takes place, which differs from the radiation of wavelength L1, wherein the at least one photochromic dye assumes a second hue. procedure after claim 1 , characterized in that the voxel exposed to the radiation of wavelength L2 or the pattern has a hue which corresponds to the respectively assigned color value of the respectively corresponding voxel of the virtual model of the real dental partial or full denture base. procedure after claim 2 , characterized in that the gingival situation is digitally recorded by means of a 3D and/or a 2D scanner, with in particular an intraoral scanning of a patient's oral cavity taking place, with the 3D and/or the 2D scanner of a CAD Interface provides 3D and/or 2D data. procedure after claim 3 , characterized in that the first color values result from the digitally recorded gingiva situation and/or the analysis information regarding the geometry, morphology and color gradients of the gingiva. procedure after claim 4 , characterized in that the method comprises the further method step: an additional assignment of second color values, wherein the additional assignment of second color values takes place according to a predefined model which is stored in a database and/or freely from a predefined template. procedure after claim 5 , characterized in that the second hue of the at least one photochromic dye, in particular the at least one photochromic pigment, corresponds to the first or second color value of the respective voxel of the virtual model of the partial or full denture base. procedure after claim 6 , characterized in that upon irradiation with the radiation of wavelength L2, the second hue of the at least one photochromic dye, in particular the at least one photochromic pigment, is permanently fixed by polymerizing the monomers in the composition. procedure after claim 7 , characterized in that the at least one photochromic dye, in particular the at least one photochromic pigment, is an organic dye or inorganic dye. procedure after claim 8 , characterized in that the at least one photochromic dye, in particular the at least one photochromic pigment, comprises an oxide of copper, samarium, terbium, praseodymium and/or europium. procedure after claim 8 , characterized in that the at least one photochromic dye, in particular the at least one photochromic pigment, naphthacenquinone, spiropyran, spirooxazine, chromene, a naphthopyran compound, a spiro[1,8a-indolizine] derivative, a spiro[1,8a-dihydrindolizine] derivative, a spiro[1,8a-tetrahydroindolizine] derivative, a spiro[fluorene-9,1[1,8a]dihydroindolizine] derivative, camphorquinone and/or phenanthrenequinone. Procedure according to one of Claims 8 until 10 , characterized in that the second hue comprises color values of the YCM color space, in particular red or yellow color nuances of the YCM color space, the RGB color space, the Munsell color space or the L*a*b* color space. Procedure according to one of Claims 8 until 11 , characterized in that at least one voxel or at least one pattern of voxels in the exposure area is exposed to radiation of wavelengths L1 and L2 by means of a surface-emitting light source (3), in particular by means of a projector and/or a beamer, the projector and /or beamer images a projection surface with locally different wavelengths and/or intensities on the surface of the photopolymerizable composition or guides it over the surface, the beamer preferably being an LED beamer, particularly preferably a UV LED beamer (1). Procedure according to one of Claims 8 until 11 , characterized in that the method comprises the step: a respective conversion of a second hue into the specific wavelength L2, wherein by using several photochromic pigments and activation by different specific wavelengths L2 and intensities different color values of the YCM color space, the RGB color space, of the Munsell color space or the L*a*b* color space. Method (100) according to any one of Claims 1 until 13 , characterized in that the method comprises the steps: - digital detection of a patient's dentition by means of a 3D scanner (101), in particular digital detection of a gingiva situation of a patient; - Analysis of at least part of the digital 3D data with regard to the morphology of the teeth as a basis for the production of a real partial or full denture base (102), the analysis being carried out manually and/or digitally, the digital analysis being an analysis of at least one area of the gingiva -Situation related to their red shades, the position of the red shades, the gradient of the red shades, their geometry and/or their morphology, obtaining gingival information, in particular in the form of gingival mapping; and/or optionally producing a virtual model of a gingival restoration or a real model of a gingival restoration as a replica of a missing gum area and/or a gingival area; wherein a) the digitally recorded 3D and/or 2D data of the gingival situation corresponds to a digital virtual model of the real dental partial or full denture base based on a gingival situation with first color values or b) the digitally recorded 3D and/or 2D data of the gingiva situation can optionally be processed digitally with regard to geometry, morphology and/or color gradients and optionally assigned analysis information with regard to geometry, morphology and color gradients of the gingiva and a digital virtual model of the real dental partial or full denture base based on a Corresponding gingiva situation with first color values, where the first color values are in the Munsell color space in a range of 5.3R-6.5YR, with file formats including STP, IGES, STL, X3D, COLLADA, WRL, OBJ, PLY, AMF. Procedure according to one of Claims 1 until 14 , characterized in that the method comprises the steps: - creating a virtual model of the dental partial or full prosthesis base on the basis of previously collected analysis data (103); - Assignment of individual color values to individual voxels (104) of the virtual model, the color values either corresponding to the originally digitally recorded color values of the scanned dentition, in particular the gingiva, are taken from a database or the assignment takes place freely at will; - converting the real color progression taken from an oral cavity scan of the patient into a data set; - Translating the digital color gradient into different wavelengths of the incident light when using photochromic pigments; - Production of the dental partial or full denture base by means of 3D stereolithography (105); and optional - adaptation of manufacturing processes to real scanned data. Dental partial or full denture base, which according to the method according to claims 1 until 15 was produced, in particular at least one prosthesis base plate, in particular a gingiva imitation as a replica of a missing gum area, a missing gingiva or a missing gingiva part. Use of at least one photochromic dye or a photopolymerizable composition comprising a photochromic dye and at least one monomer with an olefinic group in a method for producing a real dental partial and/or full denture base (100) according to claims 1 until 15 , wherein color values of the YCM color space, the RGB color space, the Munsell color space or the L*a*b* color space can be represented by using several photochromic pigments and activation by different specific wavelengths L2 and intensities.

Images